Semiconductor switches based on wide band-gap (WBG) materials, in particular unipolar materials, such as e.g. Silicon Carbide (SiC) and Gallium Nitride (GaN), provide low switching losses due to inherent advantages of these materials, such as e.g. low leakage currents at high operational temperatures and low losses at low currents. Therefore, such semiconductor switches are also suitable for high-frequency applications.
However, for instance SiC based switches are currently restricted to smaller size chips compared to bipolar Silicon (Si) based switches. For example, typical dimensions of a base area of bipolar Si switches employed in semiconductor modules are in the order of 17×17 mm2, whereas SiC switches are not exceeding half those values at best due to defect and yield issues with associated higher costs.
Moreover, the small-sized wide band-gap switches may have certain drawbacks compared to bipolar Si based switches, such as oscillatory behavior, high on-state losses at high temperatures and currents, and less fault current handling capability.
US 2014/0185346 A1 relates to a hybrid power device comprising first and second switching devices containing first and second unequal band-gap semiconductor materials. wherein the switching devices are three or more terminal switching devices of different type.
EP 0 443 155 B1 relates to a switchgear for switching on and off, having a driver for switching MOS-FET semiconductors, which are connected in parallel, and IGBT power semiconductors.
US 2004/0188706 A1 discloses a semiconductor module with an IGBT and with a wide band-gap diode, whereby the IGBT and with a wide band-gap diode are arranged on a base plate.
EP 0 637 080 A1 discloses a pressure con-tact type power module with press devices arranged on IGBT structures.